Gamogony and oocyst wal1 formation of Eimeria magna Perard, 1925 were described by light and electron microscopy for the first time in the smal1 intestinal epithelium of experimental1y infected house rabbits, Oryctolagus cuniculus from three different regions in Saudi Arabia. Sequence of events started as sexual1y differentiated fourth and fifth generation merozoites transformed into micro- or macrogamonts at 125 h.p.i., where most of the apicomplexan organel1es have been disappeared gradual1y. Microgamonts were recognizable by the presence of peripheral1y arranged nuclei and the presence of one or two centrioles between each nucleus and the limiting membrane of the gamont, while macrogamonts were recognized by the presence of wal1-forming bodies of types I and II. Both microgametogenesis and macrogametogenesis had two phases, the growth and differentiation phases. Up to 150-250 microgametes were produced per microgamont, each had 2 flagel1a. Wal1-forming bodies II and lipid globules were the first cytoplasmic inclusions to appear characterizing the development of macrogamonts. Wal1-forming bodies II, which appeared at first, were osmiophilic and distributed homogenously. Wal1-forming bodies I, which appeared later, were smal1er & distributed peripheral to the walI-forming bodies II. Oocyst wal1 formation occurred by union of the wal1 forming bodies of each type together and resulting in the formation of the bilayered oocyst wall.